Tubing catcher and anchor



Nov; 19, 1940.

Filed May 16, 1938 5 Sheets-Sheet 1 INVENTOR BY QLKW/QW ATTORNEY NOV.19, 1940. K. HER-TEL 2,221,797.

TUBING CATCHER AND ANCHOR Filed May 16, 1938 5 Sheets-Sheet 2 Rz'bizardK fferfei g /gi zw ATTORNEY Nov. 19, 1940. R. K. HERTEL 2,221,797

TUBING CATCHER AND ANCHOR Filed May 16, 1938 5 Sheets-Sheet I5 Richard Kffkrz d ATTORNEY Nov. 19, 1940.

R. K. HERTEL 2,221,797

TUBING CATCHER AND ANCHOR Filed May 16, 1938 5 Sheets-Sheet 4 Eicizarc?K firid INVENTOR A TTORNE Y Nov. 19, 1940. R. K. HERTEL TUBING CATCHERAND ANCHOR Filed May 16, 1938 Richard K Hem?! INVENTOR ATTORNEY PatentedNov. 19, 1940 TUBING CATCHER AND ANCHOR Richard K. Hertel, Vernon,Califi, assignor to Byron Jackson 00., Huntington Park, C'alif., a,corporation of Delaware Application May 16, 1938, Serial No. 208,225

24 Claims.

This invention relates generally to tubing catchers, and is directedparticularly to improvements in a tubing catcher of the type embodyingwedge slips which are automatically actuated into gripping position inthe event the string of pipe in which the catcher is incorporated shoulddrop suddenly.

In the production of oil through a string of tubing, it is commonpractice to insert a (tubing catcher in the tubing string as a safetymeasure, to catch the string should it part above the catcher or beinadvertently released at the surface. In addition to the provision forautomatic setting of the catcher when the tubing is suddenly dropped, itis customary to provide manually operable anchoring means for setting orreleasing the slips at will. An objectionable feature of anchorsheretofore employed is the necessity of rotating the tubing in oppositedirections during the setting and releasing operations. It is obviousthat rotation in one direction tends to unscrew the threading tubingcouplings, and consequently repeated setting and releasing operationsare likely to result in separation of the tubing string.

A principal object of this invention is .to provide a tubing catcherhaving anchoring means cooperating with the slips toset or release thelatter at will by successively raising and lowering the tubing and bypartially rotating the latter between the raising and loweringoperations, the direction of rotation being the same for setting and forreleasing the slips. By eliminating the reversal of the direction ofrotation, the danger of unscrewing a coupling is avoided.

Tubing anchors now in general use are provided with friction means,usually in the form of outwardly bowed fiat steel springs, engaging theouter casing and offering a predetermined resistance to movement of thetubing and the associated anchor through the casing. This type offriction means is not entirely satisfactory, chiefly because of thesmall contacting area between the springs and the casing. The springsare also liable to distortion through mishandling at the surface. Theyare usually riveted to upper and lower rings, causing concentratedflexing at these points and premature failure for this reason.

A further object of this invention is to provide a friction shoe for usewith tubing anchors, wherein the friction area is greatly increased,enabling a substantial reduction in the pressure required to be exertedby the springs to obtain the necessary frictional resistance. Byreducing the pressure the spring means may be shortened considerably andat the same time the unit stresses may be reduced, resulting in longerlife of the springs.

A still further object is to provide friction means includinginterchangeable wear shoes, whereby a single size of anchor may be usedin casings of different diameters simply by the selection of wearshoesof proper thickness.

A still further object is to improve the mounting of the slips on thetubing catcher.

Other objects and advantages will be apparent from the followingdescription, taken in conjunction with the accompanying drawings,wherein: g

Fig. 1 is an elevational View, partly in section, showing one form oftubing catcher and anchor constructed in accordance with my invention;

Fig. 2 is a view similar to Fig. 1, showing the tubing catcher anchoredin a well;

Fig. 3 is an elevational view of the nipple and head of the tubingcatcher of Figs. 1 and 2;

Figs. 4, 4(a), 4(b), 5, 5(a) and 5(b) illustrate the relative positionsassumed by the slip-actuating lugs on the anchor during the manualsetting and releasing operations;

Figs. 6,to 10 are horizontal sections taken on lines 6--6, 'l--l, 88, 99and Iii-l0, respectively, of Fig. 1;

Fig. 11 is an elevational view of the anchor sleeve and shoes;

Fig. 12 is a View in elevation of the lower portion of a tubing catcher,illustrating a modified form of anchor mechanism;

Figure 13 is a sectional development of the anchor mechanism of Fig. 12,taken at diameter J of that figure.

Referring to the drawings, and particularly to Fig. 1 thereof, a tubingcatcher is shown suspended Within a well casing I, being interposedbetween adjacent sections of a string of tubing. In the present instancethe tubing catcher and anchor are mounted on a single nipple l0extending between the adjacent ends of the tubing sections and connectedthereto by. the usual couplings, the lower coupling being indicated at12. It will be apparent, however, that the nipple may comprise upper andlower sections detachably secured together to permit the removal of thelower nipple section and the anchor in case it is desired to dispensewith the anchor.

A tubing catcher head I5 is formed on the nipple I0, either as anintegral part thereof or as a separate member rigidly secured thereto.In Fig. 3 the head I5 is shown as a separate memher, secured to thenipple by spot welding through a plurality of openings l6 formed in thehead. The head I slidably supports a plurality of anchoring slips ll,having arcuate outer faces provided with downwardly directed serrationsfor engaging the inner surface of the casing. In the present instancethe slips are three in number, equally spaced about the head. The slipsare normally disposed with their serrated faces spaced inwardly of thesurrounding casing, and are adapted to be moved upwardly and outwardlyinto engagement with the casing. For this purpose the inner surfaces ofthe slips and the outer surface of the head I. 5 are provided withcomplementary wedging surfaces directed upwardly and outwardly at aslight angle of inclination to the axis of the head.

As illustrated most clearly in Fig. 3, the head l5 has formed thereon anupper pair of wedging surfaces 2! and a lower pair of wedging surfaces22 for each slip. Each slip has an upper pair 23 and a lower pair 24 ofsurfaces corresponding to the surfaces 2! and 22. These wedging surfacesare preferably formed on inclined planes which diverge downwardly aroundthe outer surface of the nipple ID, to provide relatively long bearingsurfaces at the required steep inclination, within the small radialclearance afforded between the tubing and the casing. This constructionis similar to that described in the patent to Nelson K. Smith andRichard K. Hertel, No. 1,921,547, Aug. 8, 1933, reference being hadthereto for a more detailed description of this feature. In theaforementioned patent each slip and its cooperating seat on the head hasa pair of continuous wedge surfaces. In the present instance, however, aseries of superposed stepped surfaces is provided, as shown, to increasethe overall length of the wedge surfaces and thereby provide slipshaving substantially twice the gripping area on the casing, withoutincreasing the extent of radial movement of the slips.

The slips are maintained in sliding contact with the head throughouttheir range of setting and releasing movement by a tongue and grooveconnection with the head, In the present instance the tongue and grooveconnection is provided at the upper and lower ends of the slips, aboveand below the serrated portions thereof, as distinguished from theconstruction shown in the aforementioned patent to Nelson K. Smith andRichard K. Hertel, wherein the tongue and groove connection is formed atthe lateral edges of the wedge surfaces. The head I5 is providedadjacent its upper end with three pairs of opposed lugs 21, 28, and 29(Fig. '7), forming an undercut recess for the reception of tail-pieces39 extending upwardly from the slips. As shown at the right of Fig. .1,the inner wall of each lug is inclined to permit upward and outwardmovement of the tail-pieces during the setting movement of the slips.Adjacent the lower end of the head l5 are similar pairs of lugs 33, 34,and 35 (Fig. 8) cooperating with depending tail-pieces 36 formed on thelower ends of the slips. By this arrangement the slips are confinedagainst outward movement away from the wedge surfaces on the head.

When in their retracted positions the slips are suspended at their upperends from reins 39, each of the latter being provided at its lower endwith a hook portion 40 projecting through an eye 4| formed in the upperend of each tail-piece 30. An inwardly and upwardly projecting hookportion 42 formed on the upper extremity of each rein 39 projectsthrough a slot in the wall of an actuator 43 and is supported on theupper surface of an inwardly extending annular flange 44 formed on theinner periphery of the actuator.

To provide for automatic setting of the slips in th event the string oftubing should part above the catcher or were inadvertently released atthe surface of the well, the actuator 43 is supported on a helicalspring 41 interposed between the flange 44 and a shoulder 58 at theupper end of the head 85. The spring is of such strength that it iscompressed, as shown in Fig. l, by the weight of the actuator and slips,but will expand quickly to the position shown in Fig, 2 when relieved ofthe weight of the slips. Thus it will be seen that in the event thetubing string and catcher falls freely, the acceleration of the catcherhead l5 due to gravity will relieve the spring M of the weight of theslips, causing it to expand and raise the actuator 43, reins 39, and theslips relative to the head l5 into the relative positions shown in Fig.2. The slips are forced outwardly against the casing, the serrations onthe slips gripping the casing and arresting the fall.

A basket-type collar BI is secured to the nippic a predetermineddistance above the actuator, serving the dual purpose of limiting theupward movement of the actuator and catching any article which might beaccidentally dropped down into the well. For the latter purpose theupper surface of the collar is downwardly and inwardly beveled at 52, toprovide a pocket for retaining dropped articles. As illustrated in Fig.6, a circumferential series of openings 53 extend through the collar toprovide ample fluid passage area. i

The collar is secured to the nipple at the predetermined point by a pairof lugs 54 projecting from opposite sides of the nipple and engagingdownwardly opening bayonet slots 55 in the collar. A set screw 55retains the lugs in the horizontal legs of the slots.

It is believed that from the foregoing description of the tubing catcherthe mode of operation and the method of assembly are apparent.Particular attention is directed, however, to the manner in which theslips ll, reins 39, and actuator 43 are assembled. The reins 39 must beswung outwardly into horizontal position to insert the hooks 42 in theslots in the actuator, and when in this position the hooks 4-2] at thelower ends of the reins are also insertible in the eyes in the upperends of the slip tail-pieces 3B. When the reins are swung downwardlyagainst the outer wall of the actuator the three parts are securelylocked together, without the use of bolts or other fastening means.

The upper and lower tail-pieces 3!! and 36 on the slips aresimultaneously inserted in the undercut recesses in the lugs 2'! and 33respectively, and the slips drop into place, the back of the slipclearing the outer faces of the upper lugs 21 The collar 5! is thensecured to the nipple on the lugs 54, the spacing of the collar abovethe actuator being such as to permit the maximum upward movement of theactuator required to set the slips, but insuflicient to permit theflared tongues on the tail-pieces and to be raised above the lugs 21 and33. The collar 5!, when in place, thus insures that the parts willremain in assembled relation. As stated previously, the collar alsofunctions as a basket to catch any article, such as a tool or a slip,which might he accidentally dropped down the well, thus protecting thetubing catcher against damage or fouling by such articles.

An important feature of this invention is the novel anchoring means foreffecting manual setting of the slips at will. I have illustrated in theaccompanying drawings two forms embodying the novel features, and itwill be appreciated that still other forms may be employed.

Referring to the embodiment illustrated in Figs. 1 to 11, formed on thehead l5 below and on each side of each pair of lugs 33, 34, and 35, is apair of longitudinally extending ribs 6| and 62, there being three pairsof such ribs in the embodiment shown. The ribs of each pair define achannel 63 communicating at its upper end with the lower extremity ofthe tail-pieces 36 of each of the slips. Alternating with the channels63 are pockets 64 which terminate at their upper ends in downwardlyfacing shoulders 65 on the head l5.

An anchor sleeve 66 is slidably mounted on the nipple l6 below the headI5, and projecting upwardly from the upper end of the sleeve is aplurality of anchor fingers 61, one for each slip IT. The anchor sleeveis mounted for limited axial movement relative to the head l5, betweenan upper position wherein the fingers 61 engage the tail-pieces of theslips and force them upwardly into gripping engagement with the casing,as shown in Fig. 2, and a lower position wherein the fingers 61 arebelow the lower extremities of the ribs 6|, 62, as shown in Fig. 1. Aninwardly projecting annular flange 68 formed on the inner periphery ofthe sleeve 66 limits the downward movement of the sleeve relative to thehead 15 by engaging the upper end of the coupling l2.

A plurality of anchor shoes project outwardly of the sleeve 66 intofrictional engagement with the well casing. The preferred form of shoesand the manner of mounting them will be described hereinafter. Duringthe lowering of the string of tubing into the well, the frictionalengagement of the shoes with the well casing tends to move the anchorsleeve upwardly relative to the head, and to prevent actuation of theslips by the anchor fingers 61 at this time the fingers are inserted inthe closed pockets 64 to bear against the shoulders 65.

As stated previously, in prior devices of this type it is necessary torotate the tubing and catcher head in one direction during the settingoperation and in the opposing direction during the releasing operation,thus tending to unscrew the tubing couplings during one of these operations. I have overcome this objection in the present invention byproviding a construction wherein the catcher head is partially rotatedin the same direction for both the setting and releasing operations.Whereas in prior tubing catchers each anchor finger alternates betweenthe same set of channels and pockets, such as channels 63 and pockets64, being shifted from the pocket to the channel to effect setting ofthe slips and'shifted back to the same pocket when it is subsequentlydesired to release the slips and move the tubing to a lower position inthe well, in the present case the anchor fingers are shiftedsuccessively in the same direction around the catcher head, engaging adifferent slip on each successive setting opera.- tion. The constructionenabling this mode of manipulation will now be described.

Rotatably mounted on the head [5 below the ribs 6|, 62 is a guide sleeveH, confined between a downwardly facing shoulder 12 on the head (Fig. 1)and alock ring 13 detachably secured to the head. Equally spaced aboutthe periphery of the sleeve 1! are a plurality of guide ribs 14, one foreach of the ribs 6| and 62. In the embodiment disclosed there are sixsuch ribs. The lower ends of the ribs 61 and 62 are beveled to provideinclined abutment surfaces 15, 16, l1, l8 engageable by similarlyinclined surfaces on upwardly beveled projections on the ribs 14. Eachrib 14 is oscillatable between two of the ribs 6| and 62. A torsionspring 86 is wrapped about the head l5 between the sleeve H and the lockring 13, one end of the spring being inserted in a slot 8| in the sleeveH and the other end in a slot 82 in the lock ring 13, whereby the sleeveII is urged to the left as viewed in Fig. 3.

The lower ends of the guide ribs 14 are beveled on one side at 83, andare engageable by a cam surface 64 on one or more lugs 85 formed on theinner periphery of the anchor sleeve 66. In the event of failure of thespring 80 the cam surfaces 84 engage the lower beveled faces 83 on theguide ribs 14 during relative upward movement of the anchor, to move theguide ring to the left.

The mode of operation of the anchoring means is as follows, referencebeing had particularly to Figs. 4, 4(a), 4(2)), 5, 5(a), and 5(2)):while the tubing string and catcher are being lowered into the well, thehead l5 and anchor sleeve are in maximum telescoping relation, with theanchor fingers 61 inserted in. the pockets 64, as shown in Fig. 4. Whenthe tubing reaches the position in which it is desired to be anchored,the tubing is raised slightly. The anchor sleeve is held stationary bythe frictional engagement of the shoes with the casing, and the catcherhead is raised to position the anchor fingers below the ribs GI, 62 andbetween a pair of guide ribs 14, as indicated in Fig. 4(a). The tubingis then rotated through a partial revolution in a clockwise direction asviewed from above, or to the left, as viewed in the drawings. Duringthis rotation the guide sleeve is caused to rotate with the head by thespring 80 until one rib 14 of each pair engages the corresponding anchorfinger. Continued rotation of the head results in the ribs 6|, 62

spanning the spaces between the guide ribs 14, the

beveled faces 15, H on the ribs 6|, 62 contacting the beveledprojections on the guide ribs to limit the relative rotation of thehead, and sleeve. The parts are then in the relative positions shown inFig. 4(1)) with the anchor fingers directly below the open channels 63leading to the tail-pieces 36 on the slips.

The tubing is then lowered, as indicated in Fig. 5, causing the anchorfingers to engage the tailpieces 36 and move the slips upwardly relativeto -the head. The wedge surfaces on the head and slips force the latteroutwardly during their upward movement, into gripping engagement withthe casing. The weight of the string of tubing causes the slips to befirmly wedged between the head l5 and the casing, securely anchoring thetubin Attention is particularly directed to the relative positions ofthe guide sleeve H and ribs 'M'in Figs. 4(2)) and 5. In the formerposition the sleeve is held against rotation to the left by the anchorfingers 61. The lowering of the tubing into the position shown in Fig.5, resulting in relative upward movement of the fingers 6'l into thechannels 63, releases the sleeve H and it then snaps over to the leftunder the action of the spring, until the beveled projections on theribs 14 engage the inclined faces l6, 78 on the ribs 6|, 62. It willthus be seen that the guide sleeve is returned to its initial position,in readiness for a repetition of the above described operations.

The tubing catcher may be released simply by raising the tubing, theanchor fingers being held stationary as before. The head moves upwardlyinto the relative position shown in Fig. 5(a) with the anchor fingerspositioned between the lugs '56 on the guide sleeve, but directly belowthe tail-pieces 36.

It is frequently desired to reset the tubing catcher at a lower point inthe well, and in order to do this it is necessary to return the anchorfingers to the pockets 64 to prevent actuation of the slips by theanchor when the tubing is low cred. In prior tubing catchers this isusually a:- complished by returning the anchor fingers to the pocketsfrom which they were removed during the preceding setting operation,requiring rotation of the tubing in a direction tending to unscrew thethreaded tubing couplings.

By virtue of the guide means previously described, my invention makespossible rotation in the same direction for returning the anchor fingersto inactive position in the pockets 64. After the tubing has been raisedto the position shown in Fig. 5(a) to release the slips from engagementwith the casing, it is rotated to the left (in a clock-wise direction asviewed from above) into the position shown in Fig. 5(b). During thisretation the guide sleeve moves with the head until stopped byengagement of the ribs 14 with the anchor fingers, and relative rotationthen occurs between the head and the guide sleeve, similar to that whichoccurred during the change from the position shown in Fig. 4(a) to thatshown in Fig. Mb). The anchor fingers are now positioned directly belowthe pockets 64, and lowering the tubing causes the fingers to be movedinto the pockets. Immediately following the entry of the fingers intothe pockets, the spring 80 causes the guide sleeve to snap to the left,the parts then assuming the relative positions shown in Fig. 4. Thetubing string may then be lowered as before and reset by repeating thesequence of operations described above.

Referring again to Figs. 4 and 5, the function of the lug 85 on theanchor sleeve 66 will be apparent. If for any reason the torsion springshould fail to return the guide sleeve to its initial position shown inFigs. 4 and 5, thecam surface 8 on the lug 85 engages a guide rib M andmoves it to the dot-and-das-h position indicated at 90 in Fig. 4,whereupon subsequent relative downward movement of the anchor fingerscauses a cam surface M on the lower face of each anchor finger to engagethe guide rib and complete the movement thereof to the left. In Fig. 5the lug 85 has moved completely into the space between the guide ribsand moved them to their initial position. the extent of relativelongitudinal movement between the anchor and the head being much greaterduring the setting of the slips than when he anchor fingers are movedinto the pockets 5 Referring to the anchor mechanism illustrated inFigs. 12 and 13, it will be observed that the anchor sleeve 66 and theanchor shoes Q6 are substantially identical with that shown in Figs. 1and 11, and therefore a description thereof is deemed unnecessary.Formed on the head 15' are guide ribs 6!, 62 defining channels 63'communicating with the tailpieces 36' of the slips. Alternating with thechannels 63' are pockets 64 closed at their upper ends. Directly beloweach channel 63 is a stop lug 69 formed integral with the head I5 and Aplurality of anchor fingers 6?, one for each slip, project upwardly fromthe anchor sleeve and are adapted to be selectively inserted in thepockets 64' or the channels 63, as in the previ ously described form. Itwill be observed with reference to Fig. 12 that the anchor fingers 67 arprovided with cam surfaces 12, i3, 14 adapted to cooperate with camsurfaces 1 l on the lugs 69 and with cam surfaces 15 and 16' on theguide ribs GI, 62'.

The mode of operation of this form of the in vention will be understoodfrom Fig. 13, which is a sectional development. lustration, in thisfigure the successive relative positions of only a single anchor fingerare shown in dotted lines, but it will be understood that all of thefingers assume identical positions. Also, to simplify the description,the anchor fingers appear to move vertically and laterally. It will beunderstood, however, that the fingers are held stationary by the anchorshoes 96, and the head, including ribs SI, 62', and the stop lugs 69'are moved. While the tubing string is being lowered into the well theanchor fingers are disposed within the pockets 64, as indicated indotted lines at K. When the catcher reaches the point at which it is tobe anchored the tubing is raised a short distance, causing the anchorfingers to assume the relative position indicated at L. The tubing isthen rotated clockwise, moving the fingers to the position M, the stoplugs 69 limiting the relative rotation between the tubing and the anchorsleeve. The tubing is then lowered, whereupon the cam surfaces 72' onthe fingers engage the cam surfaces 16 on the ribs 62' caus ing furtherrotation of the tubing and head to position the fingers in the channels63 leading to the slip tail-pieces. tubing causes the anchor fingers tomove to the position N, forcing the slips upwardly and outwardly intogripping engagement with the well casing. The path of travel of thefingers during the setting operation is indicated by plain arrows. andthat during the releasing operation by feathered arrows.

To release the slips and return the anchor fingers to inactive positionwithin the pockets 84', the tubing is raised, causing relative downwardmovement of the fingers until their lower cam surfaces 13 engage the camsurfaces H on the stop lugs 69. Since the fingers are anchored againstrotation by the anchor shoes 96', the head I5 is cammed to the left, asviewed in Fig. 12, the fingers assuming the position ll. The tubing isthen lowered, causing the fingers to en gage the cam surfaces 15 on theribs 6| to produce further rotation of the head. Continued lowering of.the head and tubing moves the fingers into the pockets 64.

It will be observed in connection with Fig. 13 that, as in the formpreviously described, the anchor fingers move progressively around thehead on each setting or releasing operation, instead of alternatingbetween the same pair of pockets and channels, as in prior anchormechanisms. In this form the tubing and head are rotated from thesurface only during the setting operation, rotation being effected bycam action during the releasing operation.

It will be observed that in each of the forms described the anchorfingers move progressively around the head, resulting in rotation of thehead always in the same direction.- There is, there" For the purpose ofill Continued lowering of the fore, no danger of the tubing sectionsbeing separated by unscrewing the couplings, regardless of the number ofsuccessive setting and releasing operations.

Referring now to the novel anchor, one embodiment of which is shown inFigs. 1, 9, 10, and 11, the anchor sleeve 66 has formed therein aplurality of openings 95, herein three in number. In each opening ananchor shoe 96 is loosely mounted for limited radial movement. The shoesare of substantially less length than the openings 95, and are confinedagainst vertical movement relative to the sleeve by shoulders 91 and 98on the shoes abutting shoulders 99 and H19 formed at the juncture of theenlarged central portion and the slightly reduced end portions of theopenings 95 in the sleeve. The ends of the shoes are cut away at eachside at llll and I92 to form abutment faces I03 and H14 engageable withcomplementary abutment faces I05 and H15 (Fig. 11) above and below theshoulders 99 and I00, respectively, to limit the outward movement of theshoes.

Formed at the upper and lower ends of the openings 95 are sunkenrecesses Ill, H2 defining pockets for the reception of the ends of bowedsprings H3 which engage the inner surfaces of the shoes and urge themoutwardly. It will be observed that both ends of the springs havesliding engagement with the sleeve in the recesses Ill and H2, andconsequently there is no concentrated flexing of the springs at onepoint, such as is experienced when a bowed spring is fixedly secured atone end to an abutment, as by riveting.

By the use of the shoes 96 having an outer contour conforming to theinner contour of the casing, a large friction area is provided. Withthis large friction area the outward pressure required to exert thenecessary braking action is exceedingly low, and consequently thesprings I I3 may be relatively light and flexible. As compared to thelength and stifiness required in the springs when they contact thecasing directly, the use of the shoes as described permits theemployment of relatively short, flexible springs. When flatsprings areused, to contact the casing directly, it is apparent that full surfacecontact is not obtained, the springs contacting only at the outer edgesand providing exceedingly small friction area.

I claim:

1. In a pipe anchor, the combination of: a head, pipe-engaging jawsmounted on said head and movable from a contracted position to anexpanded, pipe-engaging position, and means for expanding said jaws,said means being movable from inactive position to active position byaxial and rotative movements of said head and movable to inactiveposition by axial and rotative movements of said head in the samedirections as said first-mentioned movements.

2. In a pipe anchor, the combination of: a head adapted to be secured toa pipe, pipe-engaging jaws mounted on said head and movable from acontracted position to an expanded position, means for expanding saidjaws, means for retaining said expanding means in inactive positionduring movement of said pipe, said expanding means being movable fromsaid inactive position into operative engagement with said jaws by axialand rotative movements of said head, and movable to inactive position byaxial and rotative movements of said head in the same directions as saidfirst mentioned movements.

3. A pipe anchor comprising: .a head adapted to be secured to an innerpipe, gripping elements mounted on said head for movement relativethereto from a contracted position to an expanded position wherein theyengage an outer pipe, anchor means slidably and rotatably connected tosaid head, said anchor means being adapted to frictionally engage saidouter, pipe, actuating means on said anchor means adapted to engage andexpand said gripping elements, said actuating means being movablesuccessively from inactive position to active position and from activeposition to inactive position by suc-' cessive axial and rotarymovements of said head relative to said anchor means, said rotarymovements being in one direction only.

4. A pipe anchor as set forth in claim 3, including guide meansassociated with said actuating means, a plurality of passage meansassociated with said head and into which said guide means is adapted tobe selectively moved to afford access of said actuating means intooperative engagement with said gripping elements, and other passagemeans associated with said head and interposed between said firstpassage means and into which said guide means is adapted to beselectively moved, said actuating means being held in inactive positionwhen said guide means is disposed in said last-named passage means.

5. A pipe anchor as set forth in claim 3, including guide meansassociated with said actuating means, passage means associated with saidhead and into which said guide means is adapted to be moved to affordaccess of said actuating means into operative engagement with saidgripping elements, and recesses associated with said head and interposedbetween said passage means, said guide means being selectivelydisposable in said passage means or said recesses.

6. A pipe anchor comprising: a head, jaws mounted on said head andmovable relative thereto from a contracted position to an expanded po-]sition, actuating elements slidably and rotatably connected to said headand adapted to selectively engage and expand said jaws or be held ininactive positions angularly spaced between said jaws, said actuatingelements being movable progressively about said head into successivejaw-expanding and inactive positions.

7. In a pipe anchor, the combination of a body member having slip seatsthereon extending upwardly and outwardly, slips mounted on said seatsfor movement between an upper expanded position and a lower contractedposition, said slips having outwardly directed gripping portionsthereon, and means for retaining said slips in substantial engagementwith their respective seats in all positions thereof, said meanscomprising a tongue extending upwardly and a second tongue extendingdownwardly from the gripping portion of each slip, said body memberhaving a pair of opposed lugs slidably embracing each of said tonguesand thereby confining the slips against outward movement Whilepermitting movement of the slips along their respectivev seats on thebody member.

8. A pipe anchor as defined in claim '7, in which each of said tonguescomprises a central portion and a laterally projecting rib on each sidethereof, and in which each of said lugs on said body member comprises ahook-shaped projection forming an undercut channel for slidablyreceiving an associated rib.

9. A pipe anchor as defined in claim 7, in

which each of said tongues comprises a central.

portion extending substantially parallel to the longitudinal axis ofsaid body member and a rib projecting laterally from each side thereof,the outer faces of said ribs being inclined upwardly and outwardly, andin which each of said lugs on the body member comprises a hookshapedprojection forming an undercut channel for slidably receiving anassociated rib, the inwardly facing wall of said projection having aninclination complementary to that of the outer face of the associatedrib.

10. A pipe anchor comprising a body member, pipe gripping jaws slidablymounted thereon and movable between contracted and expanded,pipegripping positions, extensions on said jaws above and below thepipe-gripping portions thereof, pairs of spaced lugs on said body membercoacting with said extensions to retain said jaws in assembled relationto the body member, and links pivotally connected at their lower ends tosaid upper extensions and pivotally connected at their upper ends tosaid body member.

11. A pipe anchor as defined in claim 10, in which said body memberincludes an actuator resiliently supported on said body member andmovable upwardly relative to said body member due to its own inertia onfree fall of said pipe, said links being supported by said actuator.

12. A pipe anchor comprising a head, pipegripping jaws mounted thereonand movable relative thereto between contracted and expanded positions,a tail-piece on each jaw, a pair of guide ribs on the head on oppositesides of each tail-piece and defining open-ended channels in axialalignment with said tail-pieces, recesses in said head between saidpairs of ribs, said recesses being closed at their upper ends and inopen communication at their lower ends with the adjacent channels oneach side thereof, anchor means slidably and rotatably connected to saidhead below said jaws, said anchor means comprising a sleeve, andjaw-actuating fingers projecting upwardly from said sleeve, each of saidfingers being movable in one of said channels to engage a jaw extensionduring relative axial movement between said head and anchor means, saidfingers being shiftable progressively into axial alignment with saidchannels and said recesses by successive increments of rotation of saidhead relative to said anchor means in one direction.

13. A pipe anchor as defined in claim 12, including stops on said headengageable by said fingers during said relative rotation for positioningsaid fingers in predetermined angular relation to said channels.

14. A pipe anchor as defined in claim 12, including cam surfaces oncertain of said ribs and on said fingers, for effecting said rotation asan incident to relative axial movement between said head and anchormeans.

15. A pipe anchor as defined in claim 12, in which said anchor meanscomprises friction shoes resiliently mounted on said sleeve for limitedradial movement relative thereto, cooperating surfaces on said shoes andsleeve for limiting the outward movement of the shoes, and spring meansbetween said sleeve and shoes for yieldably urging the latter radiallyoutwardly.

16. A pipe anchor comprising a head, pipegripping jaws mounted thereonfor movement relative thereto between contracted and expanded positions,and jaw actuating means comprising an. anchor sleeve slidably androtatably connected to said head, actuating means on said sleeveengageable with said jaws, angularly spaced openings in the wall of saidsleeve, friction shoes movable radially in said openings, and springmeans between the sleeve and said shoes for yieldably urging said shoesradially outwardly.

17. A friction device adapted to slidably engage the inner surface of apipe, comprising: a sleeve, a plurality of friction shoes spacedcircumferentially about said sleeve, and spring means abutting outwardlyfacing surfaces on said sleeve at spaced points and abutting in-. wardlyfacing surfaces on said shoes at points on said spring meansintermediate said spaced points.

18. A friction device comprising: a sleeve, a friction shoe supported bysaid sleeve and having a friction face normally disposed radiallyoutwardly of said sleeve, and spring means yieldingly urging said shoeoutwardly, said spring means comprising a bowed spring abutting spacedoutwardly facing surfaces on said sleeves and abutting an inwardlyfacing surface on said shoe at a point on said spring intermediate saidpoints of abutment with said sleeve.

19. A friction device comprising a supporting member, a friction shoemounted on said support for lateral movement relative thereto butconfined against longitudinal movement relative thereto, and springmeans yieldably urging said shoe outwardly, said spring means comprisinga bowed spring having slidable abutment adja cent its ends with saidsupporting member and having slidable abutment with said shoeintermediate said spring ends.

20. In a friction device for frictionally engaging the inner surface ofa tubular member, the combination of: a support, a friction shoe mountedon said support for lateral movement relative thereto, said shoe havingan outer face adapted to frictionally engage the inner surface of saidtubular member, and a bowed spring slidably abutting an inner surface onsaid shoe.

21. A pipe anchor comprising, in combination: a tubular support adaptedto be interposed between adjacent sections of a sectional pipe,pipe-engaging jaws mounted on said support for radial displacementrelative thereto, means for effecting said radial displacement of saidjaws, said means being operable by manipulation of the pipe includingrotation thereof in the same angular direction to effect both inward andoutward radial displacement of said jaws.

22. A pipe anchor for supporting a pipe within an outer casingcomprising, in combination: a tubular support adapted to be connected inthe pipe, casing-engaging jaws mounted on said support for radialdisplacement relative thereto, an anchor sleeve slidably and rotatablymounted on said support and adapted to frictionally engage the outercasing, and means operable upon relative axial and rotative movementsbetween said anchor sleeve and said support for displacing said jawsradially, said rotative movements being in the same angular direction toeffect both inward and outward radial displacement of said jaws.

23. A pipe anchor comprising, in combination: a tubular support adaptedto be connected in a sectional pipe, pipe-engaging jaws mounted on saidsupport for movement relative thereto between contracted and expandedpositions, means for expanding and contracting said jaws, said meansbeing operable to expand said jaws upon manual manipulation of said pipeto effect axial and rotative movements thereof, and optongue extendingupwardly and a second tongue extending downwardly from the grippingportion of each slip, means slidably mounted on said body above saidslips and operativcly connected with said upwardly extending tongues,and stationary guide surfaces on said body extending parallel to saidslip seats but oppositely directed with respect to said slip seats, saidguide surfaces being disposed in overlapping relation to said downwardlyextending tongues in all posi- 10 tions of said slips.

RICHARD K. HERTEL.

